The top U.S. military officer rebuffed demands from Turkey Wednesday to remove a series of American military observatory sites in northern Syria, which many see as a bulwark protecting Washington-backed Kurdish forces from a Turkish attack after U.S. troops leave.

Gen. Joseph Dunford, chairman of the Joint Chiefs of Staff, said on a visit to Ankara that the U.S. forward observation posts would remain indefinitely, despite President Trump’s order to pull out the 2,000 American troops stationed inside Syria in the near future.

Turkey has angrily rejected U.S. requests to refrain from attacking Syrian Kurds key U.S. allies in the fight against the Islamic State, also known as ISIS when the American troops leave.

President Recep Tayyip Erdogan contends the Syrian Kurds have links to Kurdish separatist forces inside Turkey that have long battled the central government.

Gen. Dunford argued in part that keeping the U.S. outposts in place would provide security for Turkey as well.

“The observation posts will continue to focus on and deter threats from Syria toward the Turkish southern border,” he reportedly told Chief of the Turkish General Staff Gen. Yasar Guler and Turkish Minister of Defense Hulusi Akar Wednesday, according to a statement from the Joint Chiefs office.

Gen. Dunford also “reiterated that the U.S. remains committed to coordinating efforts with Turkey to bring stability to northeastern Syria,” according to the statement. Military.com first reported details of Gen. Dunford’s remarks, details of which were not included in the Pentagon’s initial readout of the meeting.

National Security Adviser John R. Bolton apparently made little progress in requesting Turkey moderate its policy after a U.S. withdrawal from Syria on his visit to Ankara earlier this week.

U.S. forces have provided support to the Syrian Democratic Forces the group of Arab and Kurdish militias battling ISIS since the beginning of the war against the terror group in 2014.

Mr. Trump last month announced that U.S. forces in Syria would be withdrawn, saying their mission to defeat ISIS was largely completed. But Mr. Bolton on a weekend trip to Israel added significant new caveats to the withdrawal timeline, saying it would only take place after ISIS was fully subdued and that a plan was in place to protect U.S. allies such as the Syrian Kurds.